Liquid catalyst component, catalyst system containing said component and process for producing ethylene-α-olefin copolymer using said catalyst system

ABSTRACT

A liquid catalyst component for copolymerization of ethylene with α-olefin comprising a titanium compound represented by the following general formula: 
     
         (R.sup.1 R.sup.2 N).sub.4-(m+n) TiX.sub.m Y.sub.n 
    
     wherein R 1  and R 2  each represents a saturated hydrocarbon group having 8 to 30 carbon atoms; X represents halogen; Y represents an alkoxy group; m represents a number satisfying 1≦m≦3; n represents a number satisfying 0≦n≦2; and (m+n) satisfies 1≦(m+n)≦3. 
     Said liquid catalyst component is used in combination with an organoaluminum compound as a catalyst system for copolymerization of ethylene with α-olefin.

This is a division of application Ser. No. 07/370,021, filed Jun. 22,1989 and now U.S. Pat. No. 5,039,766.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates a liquid catalyst component, a catalyst systemcontaining said catalyst component for copolymerization of ethylene withα-olefins and a process for producing ethylene-α-olefin copolymers usingsaid catalyst system, and more particularly to a process for producingethylene-α-olefin copolymers excellent in structural randomness, weatherresistance, color protection, corrosion resistance, low temperatureproperty and dynamic property by the use of said novel catalyst system.

2. Description of the Prior Art

As a general process for producing ethylene-α-olefin copolymers, theprocess using a catalyst consisting of a compound of transition metalbelonging to Group IV to VI of the periodic table and an organometalliccompound of a metal belonging to Group I to III of the periodic table,i.e. the so-called Ziegler-Natta catalyst, is widely known.

On the other hand, ethylene-α-olefin copolymers are requested to have anarrow composition distribution from the viewpoint of practicalproperties. Thus, in the industry, they are produced by the use of acatalyst system consisting of a vanadium compound such as VCl₃, VOCl₃,VO(OR)₃ or the like and an alkylaluminum halide such as Et₃ Al₂ Cl₃ orthe like.

However, although the ethylene-α-olefin copolymers produced with theabove-mentioned catalyst system are narrow in composition distribution,the process is low in productivity because the catalyst has a lowpolymerization activity at high temperatures. Further, this process hasproblems that the residual vanadium and chlorine cause coloration of theresulting polymer, deteriorate its weather resistance and promote itscorrosion. Accordingly, ashes must be thoroughly eliminated from thepolymer in order to prevent these problems.

Further, the process using the above-mentioned catalyst system isdisadvantageous in that, if ethylene and higher α-olefin arecopolymerized with the catalyst system, the resulting copolymer is verylow in molecular weight and cannot have a satisfactory mechanicalstrength, and in addition catalyst activity is very low.

In view of the above-mentioned circumstance, a process using a catalystsystem consisting of a titanium compound or a zirconium compound and analuminum compound has been disclosed, and recently a process using acatalyst system consisting of a titanium compound or a zirconiumcompound and aluminoxane has been proposed.

However, the ethylene-α-olefin copolymers produced with these catalystsystems have a low molecular weight, and they cannot be said to besatisfactory from the viewpoint of practical properties.

On the other hand, as a process for polymerizing or copolymerizingolefins by the use of a catalyst system consisting of a compound havingtitanium-nitrogen bond and an organoaluminum compound, there have beendisclosed a process for polymerizing ethylene with a catalyst systemconsisting of an organoaluminum compound and a solid component preparedby supporting a titanium amide compound or an alkali metal salt oftitanium amide compound on magnesium halide (DE-OS 2,030,753), a processfor copolymerizing ethylene and α-olefin with a catalyst systemconsisting of aluminoxane and a titanium amide compound having π-allylligand [Japanese Patent Application Kokai (Laid-Open) No. 62-121708], aprocess for polymerizing ethylene or copolymerizing ethylene andα-olefin with a catalyst system consisting of a titanium diphenylamidecompound and an organoaluminum compound (EP-A-0 104 374), a process forpolymerizing α-olefin or copolymerizing ethylene and α-olefin with acatalyst system consisting of a titanium amide compound having an arylsubstituent and an organoaluminum compound (Japanese Patent PublicationNo. 42-22691), a process for homopolymerizing ethylene or α-olefin orcopolymerizing ethylene and α-olefin with a catalyst system consistingof an organoaluminum compound and a lower alkyl group-containingtitanium amide compound such as diethylamido-titanium trichloride andthe like [Japanese Patent Publication No. 41-5379; J. Polymer Sci., PartA-1, 241, 6 (1968)], a process for polymerizing ethylene with a catalystsystem consisting of tetrakisdiphenylamido-titanium and anorganoaluminum compound (Japanese Patent Publication No. 42-11646), etc.

However, when applied to the copolymerization of ethylene and α-olefin,all the catalyst systems disclosed in the above-mentioned references aredisadvantageous in the following points. Thus, the process of DE-OS2,030,753 is disadvantageous in that the resulting ethylene-α-olefincopolymer has a broad composition distribution; the process of JapanesePatent Application Kokai (Laid-Open) No. 62-121708 is disadvantageous inthat the resulting copolymer has a low molecular weight; and theprocesses of EP-A-O 104 374, Japanese Patent Publication No. 41-5379,Japanese Patent Publication No. 42-22691 and J. Polymer Sci., Part A-1,241, 6 (1968) are disadvantageous in that composition distribution ofthe resulting copolymer is yet unsatisfactory in narrowness. Further,the process of Japanese Patent Publication No. 42-11646 isdisadvantageous in that the resulting copolymer is yet unsatisfactory innarrowness of composition distribution and the catalyst is insufficientin activity.

SUMMARY OF THE INVENTION

In the above-mentioned situation, the object of this invention is toprovide a process for producing an ethylene-α-olefin copolymer having anarrow composition distribution and a high molecular weight and improvedin weather resistance, color protection, corrosion resistance and lowtemperature property by the use of a novel catalyst system.

According to this invention, there is provided a liquid catalystcomponent comprising:

a liquid catalyst compponent comprising a titanium compound representedby the following general formula:

    (R.sup.1 R.sup.2 N).sub.4-(m+n) TiX.sub.m Y.sub.n

wherein R¹ and R² each represents a saturated hydrocarbon group having 8to 30 carbon atoms, X represents a halogen, Y represents an alkoxygroup, m represents a number satisfying 1≦m≦3, n represents a numbersatisfying 0≦n≦2, and (m+n) satisfies 1≦(m+n)≦3; a catalyst system forcopolymerization of ethylene with α-olefin comprising:

(A) the above-mentioned liquid catalyst component and

(B) an organoaluminum compound;

as well as a process for producing an ethylene-α-olefin copolymer(hereinafter simply referred to as "copolymer") which comprisescopolymerizing ethylene with α-olefin by using said catalyst system.

Owing to the use of the catalyst system of this invention, it becomespossible to produce an ethylene-α-olefin copolymer excellent instructural randomness, and an ethylene-α-olefin copolymer excellent inweather resistance, corrosion resistance, transparency, unstickiness anddynamic properties can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an infrared absorption spectral chart of a copolymer obtainedin Example 1 of this invention;

FIGS. 2 to 4 are infrared absorption spectral charts of copolymersobtained according to prior technique in Comparative Examples 1, 3, and5; and

FIG. 5 is a flow chart diagram for facilitating to understand thisinvention which expresses a non-limitative typical example of theembodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION

(a) Liquid catalyst component (A) used in this invention is a secondaryamide group-containing titanium compound represented by the followinggeneral formula:

    (R.sup.1 R.sup.2 N).sub.4-(m+n) TiX.sub.m Y.sub.n

wherein R¹ and R², which may be identical or different from each other,each represents a saturated hydrocarbon group having 8 to 30 carbonatoms, X represents a halogen, Y represents an alkoxy group, mrepresents a number satisfying 1≦m≦3, n represents a number satisfying0≦n≦2, and (m+n) satisfies 1≦(m+n)≦3.

If R¹ and R² each represents unsaturated hydrocarbon group, acomposition distribution of the resulting copolymer is broad. In thisinvention, therefore, saturated hydrocarbon groups are used as R¹ andR². Among the saturated hydrocarbon groups, aliphatic hydrocarbon groupshaving 8 to 30 carbon atoms are preferable, and straight chain aliphaticsaturated hydrocarbon groups having 8 to 30 carbon atoms areparticularly preferable because, as the carbon chain becomes closer to astraight chain, the titanium compound becomes liquid state andcomposition distribution of the resulting copolymer becomes narrower. Asexamples of the halogen represented by X in the general formula,chlorine, bromine, iodine, etc. can be referred to, among which chlorineis most preferable from the viewpoint of catalyst activity.

As examples of the alkoxy group, methoxy, ethoxy, propoxy, butoxy,2-ethylhexyloxy and the like can be referred to. There is no limitationfrom the viewpoint of catalyst performance.

If (m+n) in the general formula is greater than 3, free TiCl₄ exists inthe titanium compound which broadens composition distribution of theresulting copolymer. If (m+n) is smaller than 1, catalyst activity islow. Accordingly, titanium compounds of which (m+n) satisfies 1≦(m+n)≦3are preferably used in this invention.

Concrete examples of such preferable titanium compound include titaniumtrichloride dioctylamido, titanium dichloride bis(dioctylamido),titanium chloride tris(dioctylamido), titanium trichloride didecylamido,titanium dichloride bis(didecylamido), titanium chloridetris(didecylamido), titanium trichloride dioctadecylamido, titaniumdichloride bis(dioctadecylamido), titanium chloridetris(dioctadecylamido), titanium dichloride dioctylamido ethoxide,titanium butoxide dichloride dioctylamido, titanium dichloridedioctylamido hexyloxide, titanium dichloride dioctylamido2-ethylhexyloxide, titanium dichloride dioctylamido decyloxide, titaniumdichloride didecylamido ethoxide, titanium dichoride didecylamidohexyloxide, titanium dichloride didecylamido 2-ethylhexyloxide, titaniumdichloride dioctadecylamido ethoxide, titanium dichloridedioctadecylamido 2-ethylhexyloxide, titanium chloride bis(dioctylamido)hexyloxide, titanium chloride bis(dioctylamido) 2-ethylhexyloxide,titanium chloride bis(dioctylamido) decyloxide, titanium chloridebis(didecylamido) hexyloxide, titanium chloride bis(didecylamido)2-ethylhexyloxide, titanium chloride bis(didecylamido) decyloxide, andthe like.

Among the above, more preferable titanium compounds are titaniumtrichloride dioctylamido, titanium dichloride bis(dioctylamido),titanium trichloride didecylamido, titanium dichloridebis(didecylamido), titanium trichloride dioctadecylamido and titaniumdichloride bis(dioctadecylamido).

As the method for synthesizing such secondary amide group-containingtitanium compounds, the methods mentioned in Japanese Patent PublicationNo. 41-5379; Japanese Patent Publication No. 42-11646; H. Buger et al.:J. Organomet. Chem. 108 (1976), 69-84; H. Buger et al.: J. Organomet.Chem. 20 (1969), 129-139; etc. can be used.

In this invention, the above-mentioned secondary amide group-containingtitanium compounds are synthesized according to the methods as mentionedabove in the following manner:

(i) A secondary amine compound represented by the general formula R⁵ R⁶NH (wherein R⁵ and R⁶ each represents a saturated hydrocarbon grouphaving 8 to 30 carbon atoms, preferably an aliphatic saturatedhydrocarbon group having 8 to 30 carbon atoms, more preferably astraight chain aliphatic hydrocarbon group having 8 to 30 carbon atomsin view of liquefaction of the formed titanium compound) is allowed toreact with

(ii) an alkyl alkali metal compound represented by the general formulaR⁷ M (wherein R⁷ represents a hydrocarbon group having 1 to 30 carbonatoms and M represents an alkali metal such as Li, K and the like) tosynthesize an amide compound of alkali metal,

(iii) and then the amide compound of alkali metal is allowed to reactwith a titanium tetrahalide represented by the general formula TiX₄(wherein X represents chlorine, bromine, iodine and the like, amongwhich chlorine is preferable).

(b) The organoaluminum compound used in this invention as catalystcomponent (B) is selected from known organoaluminum compounds.

As its preferable examples, organoaluminum compounds represented bygeneral formula R³ _(a) AlM_(3-a) and chain-like or cyclic aluminoxanesrepresented by general formula [Al(R⁴)--O]_(l) can be referred to.

In these formulas, R³ and R⁴ are hydrocarbon groups having 1 to 8 carbonatoms, and they may be identical or different from each other; M ishydrogen atom and/or alkoxy group; a is a number satisfying 0<a≦3, and lis an integer of 2 or greater.

Concrete examples of the organoaluminum compound represented by generalformula R³ _(a) AlM_(3-a) include trialkylaluminums such astrimethylaluminum, triethylaluminum, tripropylaluminum,triisobutylaluminum, trihexylaluminum and the like; dialkylaluminumhydrides such as dimethylaluminum hydride, diethylaluminum hydride,dipropylaluminum hydride, diisobutylaluminum hydride, dihexylaluminumhydride and the like; alkylaluminum alkoxides such as dimethylaluminummethoxide, methylaluminum dimethoxide, diethylaluminum methoxide,ethylaluminum dimethoxide, diisobutylaluminum methoxide,isobutylaluminum dimethoxide, dihexylaluminum methoxide, hexylaluminumdimethoxide, dimethylaluminum ethoxide, methylaluminum diethoxide,diethylaluminum ethoxide, ethylaluminum diethoxide, diisobutylaluminumethoxide, isobutylaluminum diethoxide and the like; etc.

Concrete examples of the aluminoxane represented by general formula[Al(R⁴)--O]_(l) include tetramethyldialuminoxane,tetraethyldialuminoxane, tetrabutyldialuminoxane,tetrahexyldialuminoxane, methylaluminoxane, ethylaluminoxane,butylaluminoxane, hexylaluminoxane, and the like. The amount ofcomponent (B) can be widely varied in the range of 1 to 100,000 molesper one mole of titanium atom in component (A). Preferably, however,component (B) is used in an amount ranging from 1 to 10,000 moles andmore preferably from 1 to 5,000 moles, per one mole of titanium atom incomponent (A).

(c) The monomers constituting a copolymer in this invention are ethyleneand at least one kind of α-olefin(s).

Concrete examples of said α-olefin include propylene, butene-1,pentene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1,octadecene-1, eicosene-1 and the like.

In addition to the above-mentioned monomers, a non-conjugated diene mayadditionally be copolymerized for the purpose of improving thevulcanizability of copolymer. Concrete examples of said non-conjugateddiene include dicyclopentadiene, tricyclopentadiene,5-methyl-2,5-norbornadiene, 5-methylene-2-norbornene,5-ethylidene-2-norbornene, 5-isopropenyl-2-norbornene,5-(2'-butenyl)-2-norbornene, 1,5,9-cyclododecatriene,6-methyl-4,7,8,9-tetrahydroindene, trans-1,2-divinylcyclobutane,1,4-hexadiene, 4-methyl-1,4-hexadiene, 1,3-hexadiene, 1,6-octadiene,6-methyl-1,5-heptadiene, and the like. This invention is not limited bythe compounds mentioned above.

The copolymer of this invention can have a density so widely ranging asfrom 0.85 to 0.95 (g/cm³). From the viewpoint of flexibility at lowtemperatures, however, density of the copolymer is preferably 0.85 to0.94, more preferably 0.85 to 0.92, and particularly preferably 0.85 to0.90. Further, it is preferably a rubber-like random copolymer having anarrow composition distribution of which infrared absorption spectrumshows no absorption of 730 cm⁻¹ assignable to ethylene crystal chain atall.

Further, the copolymer may involve two or more kinds of α-olefins andtwo or more kinds of non-conjugated dienes.

(d) The method for supplying the catalyst components into thepolymerization reactor is not critical, provided that the catalystcomponents must be supplied in a moisture-free state in an inert gassuch as nitrogen, argon and the like. Catalyst components (A) and (B)may be supplied either separately or after a previous mutual contact.

The polymerization can be practised at a temperature ranging from -30°C. to 300° C. However, the polymerization temperature is preferably -10°C. to 200° C. and particularly preferably 20° C. to 150° C.

Although pressure of the polymerization is not critical, a pressure ofabout 3 atmospheres to about 1,500 atmospheres is preferred from theindustrial and economical points of view.

As the mode of polymerization, both continuous and batch systems can beadopted. Further, a slurry polymerization using an inert hydrocarbonsolvent such as propane, butane, pentane, hexane, heptane or octane, aliquid phase polymerization using no solvent, and a gas phasepolymerization are all adoptable, too.

Further, a chain transfer agent such as hydrogen and the like may beadded for the purpose of regulating the molecular weight of thecopolymer of this invention.

Next, this invention will be explained in more detail by way of thefollowing examples and comparative examples.

The α-olefin content, iodine number, glass transition point andintrinsic viscosity mentioned in the examples were measured by thefollowing methods.

Thus, α-olefin content was determined from the characteristic absorptionof ethylene and α-olefin by the use of infrared spectrophotometerJASCO-302 manufactured by Nippon Bunko Kogyo K. K.

Iodine number was determined from the characteristic absorption of dieneby the use of the same infrared spectrophotometer as above.

Glass transition point (T_(g)) was measured by differential scanningcalorimeter (SSC-5000 DSC-100, manufactured by Seiko Denshi Kogyo K.K.).

Intrinsic viscosity [η] was measured in tetralin solution at 135° C.with Ubbellohde viscometer.

Density was measured according to JIS K-6760.

In the examples and comparative examples presented below, randomness inthe sequence of ethylene and α-olefin, i.e. the narrowness in thecomposition distribution, in copolymer was evaluated based on theexistence of 730 cm⁻¹ peak (absorption due to crystalline polyethylene)in infrared absorption spectrum. That is, when the absorption at 730cm⁻¹ was observable clearly or as a shoulder in the infrared absorptionspectrum of copolymer, the composition distribution was taken as broad.When the absorption was not noticeable at all, the compositiondistribution was taken as narrow.

EXAMPLE 1 (I) Synthesis of Secondary Amino Group-Containing TitaniumCompound (A)

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a dropping funnel and a thermometer with argon gas, 3.0 ml (20millimoles) of dioctylamine and 50 ml of hexane were charged.

Then, 12.6 ml (20 millimoles) of butyllithium diluted with hexane wasdropped from the dropping funnel over a period of 30 minutes, whilekeeping the inner temperature of the flask at 5° C. After dropping it,the mixture was additionally reacted at 5° C. for 2 hours and then at30° C. for 2 hours.

Subsequently, 2.2 ml (20 millimoles) of TiCl₄ diluted with hexane wasdropped from the dropping funnel into the reacted mixture over a periodof 30 minutes, while keeping the inner temperature of the flask at 5° C.After dropping it, the resulting mixture was additionally reacted at 5°C. for one hour and then at 30° C. for 2 hours. Thus, 20 millimoles(because the yield could be regarded as 100%) of a titanium compoundrepresented by composition formula (C₈ H₁₇)₂ NTiCl₃ was obtained.

(II) Copolymerization of Ethylene and Propylene

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a reflux condenser, a gas blowing tube and a thermometer withargon gas, 200 ml of n-heptane and 1.2 ml (5.0 millimoles) oftriisobutylaluminum were charged. Then, a gas mixture of ethylene (C₂ ')and propylene (C₃ ') [composition of gas phase (hereinafter, allexpressed in terms of ratio by volume) C₂ '/C₃ '=2/8] was blown into thesolution through the blowing tube till a saturation was reached. Then,0.25 millimole of the titanium compound obtained in (I) was added tostart a polymerization.

After continuing the polymerization for one hour while supplying the gasmixture at a constant temperature of 30° C., 20 ml of ethanol was addedto stop the polymerization.

The resulting polymer was washed three times with each 1,000 ml portionof a mixture consisting of 950 ml of ethanol and 50 ml of 1Nhydrochloric acid and then dried in vacuum to obtain 2.2 g of anethylene-propylene copolymer (hereinafter referred to as "EPcopolymer"). The catalyst activity per one mole of titanium atom(hereinafter, simply referred to as "activity") was 8.8×10³ g/mole Ti.

FIG. 1 illustrates an infrared absorption spectrum of the polymer thusformed. In FIG. 1, no absorption at 730 cm⁻¹ due to crystalline chain ofethylene (hereinafter, referred to as "IR₇₃₀ ") was observed,demonstrating that the polymer was a copolymer having a narrowcomposition distribution. In the copolymer, content (% by weight) ofethylene (hereinafter, simply referred to as "ethylene content") was62.1%. Its intrinsic viscosity (hereinafter, simply referred to as [η])was 2.5, density (g/cm³) (hereinafter, simply referred to as "d") was0.879, and its glass transition point (T_(g)) was -59.0° C.

EXAMPLE 2

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that composition of gas mixture C₂'/C₃ ' was equal to 5/5 and 0.5 millimoles of (C₈ H₁₇)₂ NTiCl₃ was used.As the result, 8.1 g of an EP copolymer was obtained.

Activity was 1.6×10⁴ g/mole Ti. The copolymer thus formed showed noIR₇₃₀, demonstrating that it was a copolymer having a narrow compositiondistribution. Ethylene content was 74.3%, [η]=4.4, d=0.873, and T_(g)=-59.1° C.

EXAMPLE 3

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.44 millimole of a titanium compound having a compositionformula [(C₈ H₁₇)₂ N]₂ TiCl₂. As the result, 2.64 g of an EP copolymerwas obtained.

Activity was 6.0×10³ g/mole Ti. The copolymer thus formed showed noIR₇₃₀, demonstrating that it was a copolymer having a narrow compositiondistribution. Ethylene content was 51.4%, [η]=5.4, d=0.873, and T_(g)=-59.0° C.

EXAMPLE 4

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 3, except that the triisobutylaluminum was replacedwith 5 ml of n-heptane of isobutylaluminum dimethoxide (5.0 millimoles)and 0.15 millimoles of (C₈ H₁₇)₂ NTiCl₃ was used. As the result, 3.6 gof an EP copolymer was obtained. Activity was 2.4×10⁴ g/mole Ti. Thecopolymer thus formed showed no IR₇₃₀, demonstrating that it was acopolymer having a narrow composition distribution. Ethylene content was48.6%, [η]=4.2, d=0.867, and T_(g) =-59.0° C.

EXAMPLE 5

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.44 millimole of a titanium compound having a compositionformula [(C₈ H₁₇)₂ TiCl₂ and C₂ '/C₃ ' was equal to 5/5. As the result,7.8 g of an EP copolymer was obtained. Activity was 1.8×10⁴ g/mole Ti.The copolymer thus formed showed no IR₇₃₀, demonstrating that it was acopolymer having a narrow composition distribution. Ethylene content was74.3%, [η]=4.7, d=0.901, and T_(g) =-59.1° C.

EXAMPLE 6

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.5 millimole of a titanium compound having a compositionformula (C₁₀ H₂₁)₂ NTiCl₃. As the result, 4.5 g of an EP copolymer wasobtained. Activity was 8.9×10³ g/mole Ti. The copolymer thus formedshowed no IR₇₃₀, demonstrating that it was a copolymer having a narrowcomposition distribution. Ethylene content was 72.6% [η]=2.6, d=0.870,and T_(g) =-59.1° C.

EXAMPLE 7

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.5 millimole of a titanium compound having the followingcomposition formula:

    (C.sub.8 H.sub.17).sub.2 NTi[OCH.sub.2 CH(C.sub.2 H.sub.5)C.sub.4 H.sub.9 ]Cl.sub.2

As the result, 3.4 g of an EP copolymer was obtained. Activity was6.8×10³ g/mole Ti. The copolymer thus formed showed no IR₇₃₀,demonstrating that it was a copolymer having a narrow compositiondistribution. Ethylene content was 54.7%, [η]=2.4, d=0.865, and T_(g)=-59.0° C.

COMPARATIVE EXAMPLE 1

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.25 millimole of TiCl₄. As the result, 1.2 g of an EPcopolymer was obtained. Activity was 4.5×10³ g/mole Ti. FIG. 2illustrates an infrared absorption spectrum of the copolymer thusformed. In FIG. 2, IR₇₃₀ due to crystalline ethylene chain is clearlyobserved, demonstrating that the copolymer had a broad compositiondistribution. Ethylene content was 62.5%, and [η] was 2.7.

COMPARATIVE EXAMPLE 2

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.015 millimole of a titanium compound having compositionformula (C₅ H₅)₂ TiCl₂ (Titanocenedichloride, Cp₂ TiCl₂) and thetriisobutylaluminum was replaced with methylaluminoxane (0.3 millimole)in 5 ml of toluene. As the result, 0.6 g of an EP copolymer wasobtained. Activity was 1.2×10⁴ g/mole Ti. Although the polymer obtainedherein showed no IR₇₃₀, its [η] was as low as 0.3. Ethylene content was60.1%.

COMPARATIVE EXAMPLE 3

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.05 millimole of a titanium compound having compositionformula (C₆ H₅)₂ NTiCl₃ . As the result, 1.6 g of an EP copolymer wasobtained. Activity was 3.2×10⁴ g/mole Ti. FIG. 3 illustrates an irfraredabsorption spectrum of the copolymer thus obtained. In FIG. 3, IR₇₃₀ dueto crystalline ethylene chain is somewhat clearly observed demonstratingthat the polymer had a broad composition distribution. Ethylene contentwas 59.0%, and [η] was 2.8.

COMPARATIVE EXAMPLE 4

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.58 millimole of a titanium compound having compositionformula ##STR1## As the result, 6.8 g of an EP copolymer was obtained.Activity was 1.2×10⁴ g/mole Ti. The copolymer thus obtained showedIR₇₃₀, demonstrating that it had a broad composition distribution.Ethylene content was 57.0%, and [η] was 4.8.

COMPARATIVE EXAMPLE 5

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.55 millimole of a titanium compound having compositionformula (C₂ H₅)₂ NTiCl₃. As the result, 5.5 g of an EP copolymer wasobtained. Activity was 9.9×10³ g/mole Ti. FIG. 4 illustrates an infraredabsorption spectrum of the copolymer thus obtained. In FIG. 4, IR₇₃₀ dueto crystalline ethylene chain is observed as a shoulder, demonstratingthat it is a copolymer having a broad composition distribution. Ethylenecontent was 37.9%, [η]=4.7, and d=0.862.

COMPARATIVE EXAMPLE 6

A copolymerization of ethylene and propylene was carried out in the samemanner as in Example 1 (II), except that the (C₈ H₁₇)₂ NTiCl₃ wasreplaced with 0.5 millimole of a titanium compound having compositionformula (i-C₄ H₉)₂ NTiCl₃. As the result, 10.5 g of an EP copolymer wasobtained. Activity was 2.1×10⁴ g/mole Ti. In its infrared absorptionspectrum, the copolymer thus obtained showed IR₇₃₀ as a shoulder,demonstrating that it was a copolymer having a broad compositiondistribution. Ethylene content was 71.0%, [η]=2.6, and d=0.865.

EXAMPLE 8 (III) Copolymerization of Ethylene, Propylene andNon-conjugated Diene

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a reflux condenser, a gas blowing tube and a thermometer withargon gas, 200 ml of heptane and 1.2 ml (5 millimoles) oftriisobutyl-aluminum were charged. Then, after charging 12.4 ml (100millimoles) of dicyclopentadiene as a non-conjugated diene, a gasmixture of ethylene and propylene (gas phase composition being C₂ '/C₃'=2/8) was introduced into the solution through the blowing tube until asaturation was reached. Then, 0.19 millimole of the titanium compoundhaving the composition formula (C₈ H₁₇)₂ NTiCl₃ prepared in Example 1(I) was added to start a polymerization.

Subsequently, the polymerization was continued for one hour at aconstant temperature of 30° C., while supplying the same gas mixture asabove, after which 20 ml of ethanol was added to stop thepolymerization.

The resulting copolymer was washed three times with each 1,000 mlportion of a mixture consisting of 950 ml of ethanol and 50 ml of 1Nhydrochloric acid and dried in vacuum. Thus, 1.2 g of a rubberyethylene-propylene-diene copolymer was obtained. Activity was 6.3×10³g/mole Ti.

The copolymer thus obtained showed no IR₇₃₀. content of this rubberycopolymer was 62.1%, its iodine number was 16.2, [η] was 3.0, and d was0.900.

EXAMPLE 9

A copolymerization of ethylene, propylene and non-conjugated diene wascarried out in the same manner as in Example 8, except that 13.5 ml (100millimoles) of 5-ethylidene-2-norbornene was used as a non-conjugateddiene and 0.25 millimole of the titanium compound having the compositionformula (C₈ H₁₇)₂ NTiCl₃ prepared in Example 1 (I) was added to start apolymerization. As the result, 1.5 g of a rubberyethylene-propylene-diene copolymer was obtained. Activity was 6.0×10³g/mole Ti. The copolymer thus obtained showed no IR₇₃₀. Ethylene contentwas 75.5%, iodine number was 12.1, [η]=3.8, and d=0.875.

EXAMPLE 10

A copolymerization of ethylene, propylene and non-conjugated diene wascarried out in the same manner as in Example 8, except that 1.2 ml (10millimoles) of 1,5-hexadiene was used as a non-conjugated diene and 0.19millimole of the titanium compound having the composition formula (C₈H₁₇)₂ NTiCl₃ was used. As the result, 2.8 g of a rubberyethylene-propylene-diene copolymer was obtained. Activity was 1.5×10⁴g/mole Ti. The copolymer thus obtained showed no IR₇₃₀. Ethylene contentwas 53.0%, iodine number was 8.1, [η]=3.1, and d=0.902.

EXAMPLE 11 (IV) Copolymerization of Ethylene and Butene-1

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a reflux condenser, a gas blowing tube and a thermometer withargon gas, 200 ml of heptane and 1.2 ml (5.0 millimoles) oftriisobutylaluminum were charged. Then, a gas mixture of ethylene (C₂ ')and butene-1 (C₄ ') (gas phase composition being C₂ '/C₄ '=1/8) wasintroduced into the solution through the blowing tube until a saturationwas reached, after which 0.24 millimole of the titanium compound havingcomposition formula (C₈ H₁₇)₂ NTiCl₃ prepared in Example 1 (I) was addedto start a polymerization.

Subsequently, the polymerization was continued for one hour at aconstant temperature of 30° C., while supplying the gas mixture, andthen 20 ml of ethanol was added to stop the polymerization.

The resulting polymer was washed three times with each 1,000 ml portionof a mixture consisting of 950 ml of ethanol and 50 ml of 1Nhydrochloric acid and then dried in vacuum to obtain 2.1 g of a rubberyethylene-butene-1 copolymer. Activity was 8.8×10³ g/mole Ti. Thecopolymer thus obtained showed no IR₇₃₀, demonstrating that it was acopolymer having a narrow composition distribution. Ethylene content ofthis rubbery copolymer was 60.5%, [η] was 3.7, d=0.865, and T_(g)=-69.7° C.

EXAMPLE 12 Copolymerization of Ethylene and Decene-1

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a reflux condenser, a gas blowing tube and a thermometer withargon gas, 200 ml of decene-1 and 1.2 ml (5.0 millimoles) oftriisobutylaluminum were charged. Then, ethylene gas was introduced intothe solution through the blowing tube until a saturation was reached,after which 0.025 millimole of the titanium compound having compositionformula (C₈ H₁₇)₂ NTiCl₃ prepared in Example 1 (I) was added to start apolymerization.

Subsequently, the polymerization was continued for one hour at aconstant temperature of 30° C., while supplying ethylene gas, and then20 ml of ethanol was added to stop the reaction.

The resulting polymer was washed three times with each 1,000 ml portionof a mixture consisting of 950 ml of ethanol and 50 ml of 1Nhydrochloric acid and then dried in vacuum to obtain 1.87 g of a rubberyethylene-decene-1 copolymer. Activity was 7.5×10⁴ g/mole Ti. The polymerthus obtained showed no IR₇₃₀, demonstrating that it was a copolymerhaving a narrow composition distribution. The ethylene content was67.7%, [η] was 3.7, d=0.854, and T_(g) =-69.5° C.

EXAMPLE 13 Copolymerization of Ethylene, Decene-1 and Non-conjugatedDiene

After replacing the inner atmosphere of a 300 ml flask equipped with astirrer, a reflux condenser, a gas blowing tube and a thermometer withargon gas, 50 ml of decene-1, 1.23 ml (10 millimoles) ofdicyclopentadiene and 1.2 ml (5.0 millimoles) of triisobutylaluminumwere charged. Then, ethylene gas was introduced into the solutionthrough the blowing tube until a saturation was reached, after which0.025 millimole of a titanium compound having composition formula (C₈H₁₇)₂ NTiCl₃ prepared in Example 1 (I) was added to start apolymerization.

Subsequently, the polymerization was continued for one hour at aconstant temperature of 30° C., while supplying ethylene gas, and then20 ml of ethanol was added to stop the polymerization.

The resulting polymer was washed three times with each 1,000 ml portionof a mixture consisting of 950 ml of ethanol and 50 ml of 1Nhydrochloric acid and then dried in vacuum to obtain 1.13 g of a rubberyethylene-decene-1-dicyclopentadiene copolymer. Activity was 4.5×10⁴g/mole Ti.

The copolymer thus obtained showed no IR₇₃₀, demonstrating that it was acopolymer having a narrow composition distribution. The ethylene contentwas 48.4%, and iodine number was 6.2, [η]=5.15, and d=0.869.

What is claimed is:
 1. A catalyst system for polymerizationcomprising(A) a liquid catalystic component comprising a titaniumcompound represented by the general formula

    (R.sup.1 R.sup.2 N).sub.4-(m+n) TiX.sub.m Y.sub.n

wherein R¹ and R² each represents a saturated hydrocarbon group having 8to 30 carbon atoms, X represents a halogen, Y represents an alkoxygroup, m represents a number satisfying 1≦m≦3, n represents a numbersatisfying 0≦n≦2, and (m+n) satisfies 1≦(m+n)≦3, and (B) anorganoaluminum compound.
 2. A catalyst system according to claim 1,wherein the saturated hydrocarbon group having 8 to 30 carbon atoms isan aliphatic saturated hydrocarbon group having 8 to 30 carbon atoms. 3.A catalyst system according to claim 2, wherein the aliphatic saturatedhydrocarbon group having 8 to 30 carbon atoms is a straight chainaliphatic saturated hydrocarbon group having 8 to 30 carbon atoms.
 4. Acatalyst system according to claim 1, wherein the organoaluminumcompound (B) is an organoaluminum compound represented by the generalformula R³ _(a) AlM_(3-a), or a chain-like or cyclic aluminoxane havinga structure represented by the general formula

    [Al(R.sup.4)--O].sub.l,

wherein R³ and R⁴ each represents a hydrocarbon group having 1 to 8carbon atoms, M represents hydrogen and/or an alkoxy group, a representsa number satisfying 0<a≦3, and l represents an integer of 2 or greater.5. A catalyst system according to claim 4, wherein the organoaluminumcompound represented by the general formula R³ _(a) AlM_(3-a) istrialkylaluminums, dialkylaluminum hydrides or alkylaluminum alkoxides.6. A catalyst system according to claim 4, wherein the aluminoxanerepresented by the general formula [Al(R⁴)--O]_(l) istetramethyldialuminoxane, tetraethyldialuminoxane,tetrabutyldialuminoxane, tetrahexyldialuminoxane, methylaluminoxane,ethylaluminoxane, butylaluminoxane or hexylaluminoxane.
 7. A catalystsystem according to claim 1, wherein the amount of component (B) is 1 to100,000 moles per one mole of titanium atom in component (A).